There's your answer;)
And also because they look too 'aggressive', in the wrong way, in terms of exterior styling, and way too blingy on the inside! For me, since Mercedes tried to design cars to appeal to 'youngsters' [compete with BMW in that respect], and got it badly wrong, they've never really hit the spot. They should've stuck to what they were good at instead.
Don't get me wrong, I still rate C63AMGs, but more from the era of my Brabster, than the current ones, as I much prefer the older shape.
Marco.